Garden tool power system with automatic walking function

ABSTRACT

A garden tool power system comprises a motor, a reducer and a transmission shaft. The motor transmits the power to the transmission shaft through the reducer to drive wheels on the transmission shaft. The reducer comprises a pinion connected to an output end of the motor and a gear engaged with the pinion. The transmission shaft includes left and right shafts connected with each other through a connecting shaft. The gear mounted on the connecting shaft has at least two guiding rods transversely located thereon and two centrifugal blocks located between the guiding rods. Each guiding rod has a spring surrounded therearound and each spring located between two centrifugal blocks has two opposite ends respectively abutted against the corresponding portions of the centrifugal blocks. A fixing sleeve provided on the periphery of the centrifugal blocks is mounted on the transmission shaft and has buckle structures matching with the centrifugal blocks.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 15/753,025, filed Feb. 15, 2018, which is a US national application of International Application No. PCT/CN/2016/077174 filed Mar. 23, 2016, which claims priority to CN Application Serial No. 201510504564.3, filed Aug. 18, 2015, the disclosures of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention generally relates to a power system, and more particularly to a garden tool power system with automatic walking function which can be applied to self-propelled walking lawn mowers or other self-propelled walking appliances.

BACKGROUND

With the development of domestic and overseas animal husbandry and gardens, the lawn mower used as a common mechanical tool for mowing the lawn has a good prospect in the future.

New types of lawn mowers with a battery as a power system are widely accepted by the consumers due to low working noise, smooth and reliable operation, energy conservation and environment protection. However, this kind of lawn mower has a low work efficiency and is very labor-intensive because it is manually pushed or pulled by the operator to walk forward and back, especially when worked on a lawn with a certain gradient.

SUMMARY OF INVENTION

The aim of the present invention is to provide a garden tool system with automatic walking function to improve the work efficiency due to insufficient power when manually pulled or pushed by the operator during working.

In an aspect, a garden tool power system includes a motor, a reducer and a transmission shaft. The motor transmits power to the transmission shaft through the reducer to drive wheels provided on the transmission shaft to rotate. The reducer comprises a pinion connected to an output end of the motor and a gear engaged with the pinion. The transmission shaft includes left and right shafts connected with each other through a connecting shaft. The gear is mounted on the connecting shaft and has at least two guiding rods transversely located thereon and two centrifugal blocks located between the guiding rods. Each guiding rod has a spring surrounded therearound and each of the springs is located between the two centrifugal blocks and has two opposite ends respectively abutted against a corresponding portion of the centrifugal blocks. A fixing sleeve provided on a periphery of the centrifugal blocks is mounted on the transmission shaft and has buckle structures matching with the centrifugal blocks.

In an embodiment, the connecting shaft is respectively connected with the left and right shafts through transition fit.

In an embodiment, the gear engages with the connecting shaft through clearance fit.

In an embodiment, the pinion and the gear are arranged in a housing of the reducer, and the housing comprises left and right housings assembled together through a bolt, and the pinion is assembled to the left housing via a bearing, the left and right shafts are respectively connected to the left and right housings through corresponding bearings.

In an embodiment, the fixing sleeve comprises a left fixing sleeve housed in the left housing and a right fixing sleeve housed in the right housing, and the buckle structures are respectively defined on the left and right fixing sleeves.

In an embodiment, the buckle structures are convex portions symmetrically defined on inner walls of the left and right fixing sleeves.

In an embodiment, the left and right fixing sleeves are respectively mounted to the corresponding left and right shafts through corresponding positioning pins.

The garden tool can achieve automatic walking function or self-propelling walking function when the motor is working and can be manually pulled or pushed by the operator to walk forward and back when the motor is stopped. The garden tool can easily change the working status from the self-propelling walking status to the manually walking status. And the working efficiency of the garden tool is improved and the manufacturing cost is reduced based on the simple structure of the reducer.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view of a garden tool power system with automatic walking function in accordance with the preferred embodiments of the present invention;

FIG. 2 is a cross-section view of the garden tool power system with automatic walking function shown in FIG. 1;

FIG. 3 is a schematic view of a gear shown in FIG. 2 when the garden tool is in the automatic walking working status;

FIG. 4 is another schematic view of the gear shown in FIG. 2 when the garden tool is in the manually working status; and

FIG. 5 is an exploded view of the garden tool power system with automatic walking function shown in FIG. 1.

DESCRIPTION OF EMBODIMENTS

Reference will now be made to the drawing figures to describe the embodiments of the present disclosure in detail. In the following description, the same drawing reference numerals are used for the same elements in different drawings.

In one embodiment, referring to FIGS. 1-2, a garden tool power system with automatic walking function comprises a motor 14, a reducer and a transmission shaft. The motor 14 transmits power to the transmission shaft through the reducer to drive wheels provided on the transmission shaft to rotate. The reducer includes a pinion 15 connected to an output end of the motor 14 and a gear 16 engaging with the pinion 15 and mounted on the transmission shaft.

The garden tool power system is walked automatically when the wheels provided on the transmission shaft are driven to rotate by the power transmitted from the motor 14 to the transmission shaft through the reducer. The motor 14, the reducer and the transmission shaft together form a power system of the garden tool power system. The garden tool power system can be also manually pulled or pushed to walk forward and back by the operator without the power system.

Referring to FIG. 2 and FIG. 5, the reducer has a housing for receiving the pinion 15 and the gear 16. The housing includes left and right housings 2, 12 assembled together through a bolt 9. The pinion 15 is mounted to the left housing 2 through a bearing 17.

The pinion 15 is driven to rotate by the rotation of the motor 14. The actual speed of the lawn mower can be reduced by setting the teeth number Z1 of the gear 16 and the teeth number Z2 of the pinion 15 based on the rotating speed ratio N2/N1 being equal to the transmission gear ratio Z1/Z2, wherein N2 represents the rotating speed of the pinion 15 and N1 represents the rotating speed of the gear 16.

The transmission shaft comprises left and right shafts 1, 11 respectively assembled to the left and right housings 2, 12 of the reducer through corresponding bearings 3, and a connecting shaft 13 connecting the left shaft 1 to the right shaft 11. The connecting shaft 13 is respectively connected with the left and right shafts 1, 11 through transition fit to reduce the vibration of the garden tool power system while working.

The gear 16 is assembled on the connecting shaft 13 through clearance fit to prevent the connecting shaft 13 from transmitting torque to the gear 16 while rotating.

The gear 16 has at least two guiding rods 8 transversely arranged thereon and the guiding rods 8 are fixed to the gear 16 through a pressure plate 7. Two centrifugal blocks 18 are located between the guiding rods 8. Each guiding rod 8 has a spring 6 surrounded therearound and each of the springs 6 defines two opposite ends abutting against the corresponding portions of the centrifugal blocks 18. A fixing sleeve provided on the periphery of the centrifugal blocks 18 includes a left fixing sleeve 5 mounted on the left housing 2 and a right fixing sleeve 10 mounted on the right housing 12. The left and right fixing sleeves 5, 10 are respectively fixed to the left and right shafts 1, 11 through corresponding positioning pins 4.

Each of the left and right fixing sleeves 5, 10 is provided with buckle structures on the inner wall thereof. The buckle structures are convex portions symmetrically defined on the inner walls of the left and right fixing sleeves 5, 10. The convex portions match with the centrifugal blocks 18 in a jaw-clutch manner to transmit torque.

The operation process of the garden tool power system with automatic walking function is described as follows: The motor 14 transmits kinetic energy to the pinion 15 due to the gear transmission between the motor 14 and the pinion 15 when the motor 14 is started, and the pinion 15 transmits kinetic energy to the gear 16 through the gear transmission between the pinion 15 and the gear 16, and the gear 16 is driven to rotate by the pinion 15 when the kinetic energy is transmitted from the pinion 15 to the gear 16, but the connecting shaft 13 and the left and right shafts 1, 11 respectively connected to the connecting shaft 13 are not rotated based on the clearance fit between the connecting shaft 13 and the gear 16. The garden tool power system does not walk automatically at this point.

However, the centrifugal blocks 18 mounted on the gear 16 centrifugally and outwardly move along the guiding rods 8 when overcoming the resistance from the springs 6 and are stopped moving when engaging with the convex portions of the left and right fixing sleeves 5, 10 in a jaw-clutch manner to transmit torque. The left and right shafts 1, 11 respectively drive the wheels provided thereon to rotate, so that the garden tool achieves the automatically walking function or self-propelling walking function, referring to FIG. 3. The centrifugal force of the centrifugal blocks 18 is bigger than the tensile force of the corresponding springs 6.

When the motor 14 is stopped, under the restoring force of the springs 6, the centrifugal blocks 18 can move backward to their initial positions along the guiding rods 8. And the centrifugal blocks 18 are separated from the fixing sleeves 5, 10 to stop transmitting torque, as shown in FIG. 4, so that the garden tool can be manually pulled or pushed by the operator to walk forward and back at this moment. In addition, when the garden tool is manually walked forward and back by the operator, the left and right shafts 1, 11 and the connecting shaft 13 can rotate to transmit torque due to no friction caused by the clearance fit between the gear 16 and the connecting shaft 13 and the transition fit between the connecting shaft 13 and the left and right shaft 1, 11, so as to separate the reducer from the motor 14.

In conclusion, the garden tool can achieve automatically walking function or self-propelling walking function when the motor 14 is working and can be manually pulled or pushed by the operator to walk forward and back when the motor 14 is stopped. In this manner, the garden tool can easily change the working status from the self-propelling walking status to manually walking status. And the working efficiency of the garden tool is improved and the manufacturing cost is reduced basing on the simple structure of the reducer.

It is to be understood, however, that even though numerous characteristics and advantages of preferred and exemplary embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail within the principles of present disclosure to the full extent indicated by the broadest general meaning of the terms in which the appended claims are expressed. 

We claim:
 1. A garden tool power system having a self-propelling walking status and a manually walking status, comprising: a motor, a transmission shaft coupled to the motor; a reducer connecting the transmission shaft to the motor and transmitting power from the motor to the transmission shaft when the system is in the self-propelling walking status, the reducer including a pinion connected to the motor and a gear mounted on the transmission shaft and engaging with the pinion; and a plurality of wheels respectively located at two opposite ends of the transmission shaft and being driven to synchronously rotate with the transmission shaft; wherein the gear has a plurality of centrifugal blocks mounted thereon, and wherein when the system is in the self-propelling walking status, the plurality of centrifugal blocks are in a first state and the transmission shaft is driven by the motor to rotate the plurality of wheels; and wherein when the system is in the manually walking status, the plurality of centrifugal blocks are in a second state and the transmission shaft is driven to rotate by the plurality of wheels; wherein the transmission shaft has a fixing sleeve mounted thereon, and the plurality of centrifugal blocks abut against the fixing sleeve when in the first state and the plurality of centrifugal blocks separate from the fixing sleeve when in the second state; and wherein the fixing sleeve is provided on a periphery of the plurality of centrifugal blocks and has a plurality of buckle structures respectively matching with corresponding portions of each of the plurality of centrifugal blocks.
 2. A garden tool power system according to claim 1, wherein each of the plurality of buckle structures includes a plurality of protrusions extending from an inner wall of the fixing sleeve and a plurality of notches formed between two adjacent protrusions.
 3. A garden tool system according to claim 2, wherein each of the plurality of centrifugal blocks has a plurality of convex portions located thereon, and wherein each of the plurality of convex portions is received in the corresponding notch and abuts against one of the plurality of protrusions when the plurality of centrifugal blocks are in the first state.
 4. A garden tool power system according to claim 3, wherein the plurality of convex portions separate away from the fixing sleeve along a longitudinal axis direction of the transmission shaft when the plurality of centrifugal blocks are in the second state.
 5. A garden tool power system according to claim 1, wherein the transmission shaft includes left and right shafts connected with each other through a connecting shaft, and wherein the gear is mounted on the connecting shaft.
 6. A garden tool power system according to claim 5, wherein the fixing sleeve further comprises a left sleeve mounted on the left shaft and the system further comprises a right sleeve mounted on the right shaft, and wherein the plurality of buckle structures are respectively and symmetrically formed on an inner wall of the left and right shafts.
 7. A garden tool power system according to claim 6, wherein the left and right fixing sleeves are respectively mounted to the corresponding left and right shafts through corresponding positioning pins.
 8. A garden tool power system having a self-propelling walking status and a manually walking status, comprising: a motor, a transmission shaft coupled to the motor; a reducer connecting the transmission shaft to the motor and transmitting power from the motor to the transmission shaft when the system is in the self-propelling walking status, the reducer including a pinion connected to the motor and a gear mounted on the transmission shaft and engaging with the pinion; and a plurality of wheels respectively located at two opposite ends of the transmission shaft and being driven to synchronously rotate with the transmission shaft; wherein the gear has a plurality of centrifugal blocks mounted thereon, and wherein when the system is in the self-propelling walking status, the centrifugal blocks are in a first state and the transmission shaft is driven by the motor to rotate the wheels; and wherein when the system is in the manually walking status, the centrifugal blocks are in a second state and the transmission shaft is driven to rotate by the wheels; wherein the transmission shaft has a fixing sleeve mounted thereon, and wherein the centrifugal blocks abut against the fixing sleeve when in the first state; and wherein the centrifugal blocks separate from the fixing sleeve when in the second state and the gear has at least one guiding rod transversely located thereon, and wherein the plurality of centrifugal blocks are respectively located at two opposite ends of the corresponding guiding rod, and wherein each of the at least one guiding rod has a spring surrounded therearound and each said spring located between two of the plurality of centrifugal blocks has two opposite ends respectively abutted against corresponding portions of each of the two centrifugal blocks.
 9. A garden tool power system according to claim 8, wherein each said spring is stretched when the plurality of centrifugal blocks are in the first state and wherein each said spring recovers elastic deformation when the plurality of centrifugal blocks are in the second state. 